My father challenged me today on JD 10 to solve this riddle. I’m sure it slipped out of his mind that I’m majoring in Accounting. But hey, a little extra cash won’t hurt anybody
By the way, I found it so easy that it took me couple of seconds to figure it out. And yes I got the money!
Here goes:
A man wanted to get into his office building, but he had forgotten his password. However, he did remember five clues:
- The fifth number plus the third number equals fourteen.
- The fourth number is one more than the second number.
- The first number is one less than twice the second number.
- The second number plus the third number equals ten.
- The sum of all five numbers is 30.What are the five numbers?
So go ahead and use your brain to solve something for a change
But if you are fed up by now—and cursing me—hit the Read More button to see the solution.
Okay, so let’s start simple.
Let’s say that the 5 numbers are A B C D E
1) We take the clues one by one:
- The fifth number plus the third number equals fourteen → E + C = 14
- The fourth number is one more than the second number → D = B + 1
- The first number is one less than twice the second number → A = 2B – 1
- The second number plus the third number equals ten → B + C = 10
- The sum of all five numbers is 30 → A + B + C + D + E = 30
2) We arrange the 4th equation to C = 10 – B and then solve for the 1st equation to become E + 10 – B = 14
3) We solve for all the equations in term of B:
– E + 10 – B = 14 → E = 4 + B
- D = B +1
- A = 2B – 1
– C = 10 – B
4) We then substitute the previous equations in A + B + C + D + E = 30
A + B + C + D + E = 30
(2B – 1) + (B) + (10 – B) + (B + 1) + (4 + B) = 30
2B – 1 + B + 10 – B + B + 1 + 4 + B = 30
2B - 1 + B + 10 - B + B + 1 + 4 + B = 30
4B + 14 = 30
B = 4
5) We then simply figure out the rest of the terms:
– A = 2B – 1 → A = 7
- C = 10 – B → B = 6
- D = B + 1 → D = 5
– E = 4 + B → E = 8
6) Here we go, the password is: 74658
Hope you like it just as I did… Okay okay just don’t hit me











February 28, 2008 at 9:06 am
OMG this is too much for me hehhe
I didn’t even think about it , but I like it , I will challenge my coworkers to solve it
Clever Jasim (Smallah)!
February 28, 2008 at 9:49 am
Lool
yeah you do that and tell them it’s so easy, I don’t know how you can’t solve it
Well thank you
February 28, 2008 at 3:20 pm
kont fayet ashoofak 3ayesh wella la2 !!
I read the first line and I couldn’t complete…I can’t force my brain to work more today looool
February 28, 2008 at 3:31 pm
Le soo2 7azkom lessatni 3ayesh
Tayeb not a problem, try it tomorrow
February 29, 2008 at 12:39 am
I HATE Math and Numbers and anything/everything in between. I tried to solve it, but my attempt was a failure apparently. Actually, I got bored when I started reading the third clue. I really feel stupid now
AND IT IS ALL YOUR FAULT
I will show it to my brother, he claims to be the SMARTEST person on the face of the planet
-As if I need Math lovers hanging around me-
February 29, 2008 at 1:28 am
I solved it ..accounting major weirdos
it’s not the einstein riddle though
Thanks i haven’t used my brain since i quit my job
February 29, 2008 at 9:10 am
Hala,
No don’t feel stupid, bil 3aks you should feel smarter because you tried! We guys, at one point or another, are the smartest on the face of Earth
Maha,
I’m one of the weirdos, and I’m proud of it
It’s easy, no?
March 1, 2008 at 3:01 pm
5 variables, 5 equations.. easyyy
anyway it reminded me of the card game Hand, when you wanted to know the sum of 5 sequantial cards multiply the middle one with the number of cards, so mid number is 6, 6 times 5 = 30
thanks i have not done any math in ages
March 1, 2008 at 3:09 pm
I know it’s easy, that’s what I’ve been telling people!
About the Hand game thing, yeah I know because when the numbers are consequent, their median = average, so when you multiply their average by their number (N) you get their sum.. Piece of cake..
Look I’m no nerd
March 2, 2008 at 5:16 am
Jasim, my password is ALSO made out of 6 numbers…. looool, bas im not giving you clues. You’re dangerous!
eh eh ok, I said mashAllah. Relax!
March 2, 2008 at 8:04 am
Thank you.
As for your password, it’s okay no need for 5 clues, I can work with one. :p
March 3, 2008 at 8:32 pm
Ah, simultaneous equations and substitution, haha.
You should see this website, lots of nice math challenges:
http://mathschallenge.net/
And if you like programming and math, like me, see Project Euler:
http://projecteuler.net/
Good luck.
March 4, 2008 at 11:02 pm
Khaled, thank you so much for the website, you have given me a treasure.
Well I’m not mush into programming, well… I don’t know anything about programming, but I can say that I adore Mathematics.
Thanks.